The powertrain of a motor vehicle refers to a group of components that generate and deliver power to the road surface to propel the vehicle along the road. In general, the powertrain includes a power source that generates or provides power, and a transmission that transmits the power to the drive wheels of the vehicle. The transmission is a speed and torque changing device that converts the speed and torque produced by the power source to that desired by the vehicle. Typically, an input shaft (or drive shaft) inputs the power from the power source to the transmission and an output shaft outputs the power from the transmission. The output shaft is connected to the driving wheels through a differential. The transmission includes multiple gears that selectively engage or mesh to convert the speed/torque produced by the power source to that suitable for different driving conditions (accelerating, cruising, etc.). The operator of the vehicle, or a control unit of the vehicle, may initiate a gear change in the transmission in response to driving conditions.
When the power source of the vehicle is an internal combustion engine, the naturally occurring vibrations or torque fluctuations in the input shaft assist in engaging (or meshing) the gears in the transmission. However, when the power source is an electric motor, the input shaft may not carry sufficient vibrations and fluctuations to assist in gear engagement. Further, the speed of the input shaft may be more accurately controller by an electric motor. These properties of electric motor drives may result in binding or partial engagement of the gears in the transmission. Binding or partial engagement of the gears may cause damage to the transmission and decrease vehicle reliability due to failure to transfer power efficiently to the wheels. Embodiments of the current disclosure may alleviate the problems discussed above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem.